Lock for automatic telephone-switch shafts.



No. 801,308. PATENTED OCT. 10, 1905. J. BRIGKSON. LOCK FOR AUTOMATIC TELEPHONE SWITCH SHAFTS.

APPLICATION FILED DEO.31, 1904.

UNITED STATES PATENT rr on.

JOHN ERICKSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO AUTOMATIC ELEC- TRIC COMPANY, OF CHICAGO, ILLINOIS.

LOOK FOR AUTOMATIC TELEPHONE-SWITCH SHAFTS.

Specification of Letters Patent.

Patented Oct. 10, 1905.

Application filed December 31, 1904:. Serial No. 239,132-

To all whom it may concern:

Be it known that 1, JOHN ERIOKSON, a citizen of the United States of America, and a resident of Chicago, Cook county, Illinois, have invented a certain new and useful Improvement in Looks for Automatic Telephone- 'Switch Shafts, of which the following is a specification.

My invention relates to automatic telephone systems which embody or have suitable connection with means for transmitting firealarm signals. It is a matter of common knowledge that in certain automatic telephone-exchange systems it is the practice to so construct or arrange the apparatus that any subscriber can, by calling a predetermined number, cause the so-called first selector-switch to make connection with a socalled special connectorswitch. After this the subscriber may, by pushing a button, operate the said special connector-. switch, and thereby ring or signal all of the different fire-alarm stations. hen this has been done and after all of the said fire-alarm stations have answered their respective telephones, the subscriber can simultaneously give the different stations the location of the Generally stated, the object of my invention is to prevent the subscriber or party thus sending in the alarm to the different firealarm stations from making another call and from returning the apparatus to its normal condition until after the number of such subscriber or calling party has been recorded by the switchboard attendant at the exchange or central station, it being obvious that a pro vision of this character is desirable in order to prevent malicious tampering with the firealarm signaling apparatus and the sending in of false alarms, and a special object is to provide a selector-switch having a rotary and endwise movable shaft and having also a catch or look device for locking the said shaft in the position to which it is adjusted when the subscriber to whom such selector-switch is allotted desires to communicate with the different fire-alarm stations, and whereby the said switch cannot be returned to its normal position until the said catch or look device is manually released by the switchboard attendant at the exchange or central station, and it is also an object to provide certain details and features tending to increase the general efliciency of a device of this particular character.

In the accompanying drawings, Figure 1 is a front elevation of the rotary and end wisemovable shaft of a so called selectorswitch, showing adjacent portions of the body-frame and illustrating one form of catch or look device for locking the said shaft in the position necessary for connecting the subscriber with the fire-alarm stations. Fig. 2 is a perspective of the catch or look device shown in Fig. 1. Fig. 3 is a side elevation of the lock device shown in Fig. 1, illustrating the manner in which the said catch or look device locks the switch-shaft in an elevated position. Fig. 4: is a view similar to Fig. 1, but illustrates another form of catch or look device. Fig. 5 illustrates the manner in which the switch-shaft disengages itself from the catch or look device shown in Fig. 4 when the said shaft is to be used in establishing telephonic connection between subscribers. Fig. 6 is a perspective of the catch or look device shown in Figs. I and 5, show ing also adjacent portions of the switch.

As thus illustrated, it will be seen that the switch, with the exception of the catch or lock device, is of that well-known type in which a rotary and endwise-movable shaft is employed as an element whereby the telephone sub scriber may establish connection with a trunkline or with the line of some other subscriber. The said shaft A is, it will be seen, arranged vertically in the usual manner and mounted in upper and lower bearings 60 and a. As shown, the said bearings are secured to the top and bottom of a frame or body B, which latter, it will be understood, is also employed for supporting various other necessary and well-known elements of an automatic telephone-switch of this particular character. The locking-dog C, connected with and operated by any suitable known or approved means, is adapted to engage the series of circular ratchet-teeth c on the said shaft and is employed in looking the said shaft against downward movement after it has been given the extent of upward step-by-step movement necessary in establishing connection between two subscribers lines. The said upward stepbystep movement can be produced in any ordinary or desired manner, and it will also be seen that the desired rotation of the said shaft in a step-by-step manner can be accomplished by means of any of theknown or approved devices. Another locking-dog D engages the teeth on the cylindrical enlargement (4 carried by the said shaft. ith this arrangement the said shaft is also locked against back rotation after it has been rotated in a step-by-step manner to the extent necessary in establishing the desired telephonic connection. IVith the an rangement shown it will be seen that the teeth 0, are ten in number, it being understood that the switch is provided with banks of contacts divided into ten levels with ten positions or contacts in each level. Consequently the oylindrical enlargement a may have ten teeth, whereby the shaft may be rotated by means of ten consecutive impulses or by a less numher, as may be required. As will be readily understood, the switch as a whole includes an electrical arrangement whereby when the subscribers are through talking the calling subscriber may then operate or release the dogs C and D, and thereby restore the switch shaft to its normal position. Preferably the switch shown and the one whereby I accomplish the main object of my invention is the so-called first selectorthat is to say, that particular automatic switch which is appropriated to the use of a single subscriber. In other words, each so-called first selector is not common to two or more subscribers lines, but is individual to a single subscriber.

Ordinarily in the operation of simply connecting up one subscriberss line with another the said first selector may operate in the usual and well-known manner. As previously explained, however, it is desirable in certain cases to so arrange the apparatus that the subscriber may, by calling a special or predetermined number, cause the first selector to establish connection with a so-called special connector-switch-that is to say, a connector which is only used in case one of the subscribers of the exchange desires to transmit a fire-alarm signal to the different firealarm stations. This may be accomplished in various waysas, for example, by appropriating the tenth or uppermost level of the switch-contacts for use only in transmitting fire-alarm signals. Again, the first or lowermost level of the bank-contacts in the switch may be employed solely for the purpose of connecting the subscribers line with the said special special connector. In either case, however, it will be seen that whatever level is appropriated solely for fire-alarm purposes the said level will never be employed in giving service between the different telephone subscribers.

In Figs. 1 to 3, inclusive, the construction is such that the tenth or uppermost level of the bank-contacts is employed only for transmitting fire-alarm signals. In Figs. 4: to 6, inclusive, the first or lowermost level of the bankcontacts in the switch is appropriated for use only 1n giving fire-alarm signals.

In a system where some provision of the foregoing character is made it is evident that more or less trouble and annoyance arelikely to be experienced if no means are provided tending to prevent malicious tampering with the fire-alarm apparatus and the transmission of false fire-alarm signals. For this reason I preferably provide the said first selector with a suitable catch or lock device and adapt the same to so lock the shaft of the switch in the position to which it may have been moved or adjusted for the purpose of establishing a fire-alarm connection that the subscriber cannot then restore the switch to its normal position' until after the attendant at the exchange or central station has' manually released the said catch or look device. It will be under stood, of course, that the said catch or look device is only brought into action when the switch-shaft is moved or adjusted to the position necessary for giving the fire-alarm, and consequently does not at all other times have anything to do or in any way conflict with the operation of establishing connection between two subscribers lines. The said catch or lock device may be of any suitable form or construction and operate in any suitable or desired manner. For example, it may be of the form shown in Fig. 2 and applied as shown in Figs. 1 and 3. In such case the said catch or look device is in the nature of a spring-dog E and is provided with a body portion 6, secured in place by one of the upper screws of the frame structure, and with a handle portion 0. hen the shaft A has been raised to the tenth level, the said dog E will then engage the under side of the collar (0, as shown in Fig. 3, the said collar being applied to the shaft at a point just above the series of ratchet-teeth a This will prevent the shaft from being restored to its normal position until the switchboard attendant at the exchange or central station manually disengages the dog E from beneath the said collar on the shaft. In other words, the subscriber after throwing the said shaft into the position necessary for communicating with the fire-alarm stations is then powerless to restore the switch to its normal position. Only the switchboard attendant at the exchange or central station can, by grasping the handle portion 0, release this shaft and restore the switch to its normal condition. In this way the switchboard attendant can always be certain of making a record of the number of every subscribers station from which a firealarm is turned in or transmitted to the firealarm stations. This obviously will reduce to a minimum the tendency toward malicious tampering with the fire-alarm apparatus and the transmission of false fire alarm signals. Again, the said catch or lock device may be of the form shown in Figs. 4, 5, and 6. In this case the catch or lock device is in the nature of a spring-dog F and is provided with a body portion f, adapted to be secured to the frame scriber.

or body, and also with a handle portion f. The said spring-dog F can be located in position to normally engage additional teeth on the cylindrical enlargement a of the shaft. In this way and with the first level of the switch contacts appropriated solely to the purpose of connecting upthe subscribers with the fire-alarm stations, which is the case in Figs. i, 5, and 6, itis evident that when the shaft is rotated without being given any vertical movement the spring-dog F will hold or lockit against back rotation. In this way the subscriber can use the first level for establishing connection with the fire-alarm stations and after so doing cannot then restore the switch to its normal condition until after the switchboard attendant at the exchange or central station has disengaged the spring-dog F from the teeth carried by the shaft. In either case therefore it is evident that a spring-d 0g is employed and adapted to engage some operative portion of the switch in such manner that the switch as a whole cannot be restored to its normal condition after having been employed for establishing connection with the fire-alarm stations until after the switchboard attendant has inspected the first selector of the subscribers station from which the fire-alarm has been sent in and until after the switchboard attendant has manually disengaged or released the spring-clog, and thereby placed the switch as a whole in condition to be restored in the ordinary manner and through the medium of the devices or means usually employed for such purpose and under the control of the sub- Obviously, therefore, I provide a first selector or individual switch for automatic telephone systems of such character that when used for connecting the subscribers line with one or more fire-alarm stations it cannot then be restored to its normal condition or again used by the subscriber until after it has been located and inspected by the switchboard attendant and until after the said attendant has made a record of the number of the subscribers station with which the said first selector or individual switch is connected. It being thus impossible to transmit fire-alarm signals to fire-alarm stations without leaving a record of the number of the station or telephone from whence the signal was sent, it is evident that the number of false signals and all malicious tampering with the fire-alarm apparatus and signals willat least be reduced to a minimum.

What I claim as my invention is 1. An individual switch for automatic telephone systems, said switch being provided with an operative part under the control of the subscriber, and adapted to be given a plurality of positions, one of said positions being appropriated solely for the purpose of transmitting alarms or special signals, and a spring-dog adapted to hold said operative part in said appropriated position until manually released.

2. An individual switch for automatic telephone systems, comprising an operative part under the control of the subscriber, and adapted to be given various positions, accordin g to the character of the connection desired, one or more of said positions being appropriated solely for the purpose of giving alarms or special signals, and a locking device not under the control of the subscriber and adapted to hold said operative part in the position to which it may be moved for the said purpose of giving an alarm or special signal.

3. An individual switch for automatic telephone systems, comprising means under the control of the subscriber for establishing any one of a number of possible connections, and a locking device adapted, when a connection of a certain character is made, to prevent the subscriber from restoring the switch to its normal condition.

4:. A first selector-switch for automatic telephone systems, comprising a rotary and endwise-movable shaft, said shaft being adapted to be given various positions, according to the character of the connection desired, and a spring-dog adapted, when a connection of a certain character is established, to engage a rigid part of the shaft structure, and thereby lock the latter against restoration to its normal position until manually released.

5. A switch for automatic telephone systems, comprising means under the control of the subscriber for establishing any one of a number of possible connections, and means adapted, when a connection of a certain character is established, to prevent the subscriber from restoring the switchto its normal condition, but the switch being releasable by the subscriber when used for making other connections.

6. A switching device for establishing electrical connection, and a locking device adapted, when a connection of a certain character is made, to prevent the person who brought about the connection from restoring the switch to its normal condition, but the switch being releasable by the subscriber when used for making other connections.

Signed by me at Chicago, Cook county, Illinois, this 1st day of December, 1904.

JOHN ERICKSON.

WVitnesses:

W. LEE CAMPBELL, R. C. GIFFoRD. 

